Abstract: An auto-zeroed ohmmeter is comprised of a current source having first and second leads for connection to respective terminals of an unknown resistor to generate first and second voltages at the terminals. A sensing circuit having third and fourth leads connects to the terminals of the unknown resistor and scales the first and second voltages to third and fourth voltages respectively. A ramp generator circuit is coupled to the sensing circuit and generates a ramp voltage with a slope proportional to the difference between the fourth voltage and a multiple of the third voltage. This ramp is generated for a time period of predetermined duration to thereby produce a reference point voltage at the end of the time period.